Duffy (shoulder) was placed on the 10-day disabled list Monday, Jeffrey Flanagan of MLB.com reports.

EDGE Analysis

Duffy has been dealing with shoulder tendinitis for the past few weeks, so the 35-win Royals decided to play it safe with their ace and send him to the shelf. It's unclear how long Duffy will be sidelined, but he'll be eligible to return Aug. 20. Glenn Sparkman was recalled from Triple-A Omaha in a corresponding roster move and will temporarily take Duffy's spot in the rotation.